Sunrise - I'll have to get hold of the original RAW file to try to rescue the sky a bit. I have a series over a few minutes from that location so one that's got the sun pooping through a little less may be better...

Get there early and you'll have the locals bringing you a seat, breakfast menu and hot Cambodian coffee. Get there late in high season and you'll be assaulted by tripods and struggle to get a clear shot.

Hint - make sure you take a torch if you go early. It's not that easy to see where the land ends and the pond/snakes start!

I think that I need to make a walking tour in clear daylight so I have somekind of idea where the sun is going to rise and what kind of plase Ankor wat is.

If you mean bitt by mosquitos. I don't try to too sure about my self, but we have some of them here as well. Got guite some experiense of them while I were serving in Finnish army. - Snakes are a different story... Don't want to get bitten by any of those. I think headlamp is going to be huge help so I have both my hands free.